Carson pile regulator



July 26, 1955 H. G. HAAS ET AL 2,714,146

CARBON PILE REGULATOR Filed March 1, 1951 FIG. 2

FIG.|

IN V EN TORS HAROLD G. HAAS W/LL/AM G. NE/LD RA/E) United. States Patent Ofifice 2,7i4d46 Patented July 26, 1955 The present invention relates to electrical regulators and particularly to regulators of the so-called carbon pile type.

Carbon pile regulators have come into widespread use for such purposes as controlling the voltage of the output of generators and also in the control of current. All of these carbon pile regulators operate on the principle of varying the pressure applied to the carbon pile. The range of effective pressure on the pile being the regulating range of the regulator. One end of the carbon pile is relatively fixed, the other end being operatively associated with an armature to apply pressure on the carbon pile. The armature is biased in one direction by a spring and in the other by an electromagnet.

The conventional carbon pile regulator of the aforenoted type usually has the carbon pile mounted in a metal housing having cooling fins thereon and the carbon pile adjusting screw mounted on the housing operatively associated with the fixed end of the carbon pile.

Due to internal heating and ambient temperature changes, the pile housing expands and contracts thereby causing movement of the carbon pile adjusting screw. This movement of the carbon pile adjusting screw affects the calibrating of the regulator and causes erratic operation thereof.

In order to overcome the aforenoted disadvantage, the carbon pile adjusting screw and pressure plate are mounted independently of the housing structure by means of posts having a relatively low coefficient of expansion.

An object of the present invention improved carbon pile regulator.

Another object of the invention is to provide an im-- proved carbon pile regulator that is not affected by temperature changes.

Another object of the invention is to provide novel mounting means for the adjusting screw and pressure plate of a carbon pile regulator.

Another object of the invention is to provide a temperature compensated carbon pile regulator.

The above and other objects and features of the invention will appear more fully hereinafter from a consideration of the following description taken in connection with the accompanying drawing wherein two embodiments of the invention are illustrated by way of example.

in the drawings:

Figure 1 is a longitudinal sectional view of a carbon pile regulator constructed in accordance with one embodiment of the present invention.

Figure 2 is a longitudinal sectional View of a carbon pile regulator constructed in accordance with another embodiment of the invention.

Referring now to Figure l of the drawing, a carbon pile regulator is indicated generaly by the numeral 5, and comprises a stack 6 of carbon discs 7 and an electromagnet assembly 8 disposed to control the pressure on the stack 6.

The stack 6 is disposed between a relatively fixed presis to provide an Separating the case 18 magnetic sticking of the sure plate or button 9 of carbon or the like and a movable pressure plate or button 10, also of carbon, and are mounted in a ceramic tube or sleeve 11. The sleeve 11 is surrounded by a housing 12 of aluminum or the like. The housing 12 is provided with fins 13 for dissipating heat from the stack 6.

The pressure applied to the stack 6 through the button 10 is controlled by the operation of the electromagnet 8 in opposition to a spring member 14. The electromagnet .8 comprises an end plate 15 and a central core member 16 threaded therein which projects through an electromagnet winding 17 also carried by the plate 15. A casing 18 encloses the electromagnet 8 and has an annular opening 19 concentric with the core 16.

The spring member 14 is preferably of the diaphragm type and seats on a beveled ring member 20. The spring member 14 carries an armature member 21 which is spaced in operative relation to the core 16. In addition, the armature member 21 supports the carbon button 10. and ring 20 and extending across the air gap between the armature 21 and the core 16 is a suitable non-magnetic member 22 preferably formed of brass for providing means for limiting the minimum air gap between the armature 21 and the core 16 to prevent armature 21 as might occur should the air gap be reduced below the minimum safe level.

The housing 12 has a counterbore portion 23 adapted to fit over the armature assembly. The housing 12 and case 18 are secured together by bolts 24 or in any other conventional manner.

A plate 25 of suitable insulating material is mounted on posts 26 by screws 27. The posts are formed of a material having a very low temperature coeflicient of expansion and may be formed, for instance, of the nickel iron alloy sold under the trade name of Invar. Only one of the posts is shown; it is understood, however, that a plurality may be used. Most applications would require three or four. The other end of the posts 26 are secured to a plate 28 integral with the housing 12 by screws 29. The posts 26 project freely through openings 30 in the fins 13.

A cap 31 is secured. to the plate 25 by screws 32. The cap 31 screw threadedly engages a screw 33 which may be locked in position by a suitable flat spring lock indicated by the numeral The screw 33 has a cleft portion 35 for adjusting purposes. Also the screw 33 has a recessed portion adapted to receive the carbon button 9. A cover 37 may be secured over the screw 33 in any conventional manner.

In operation, the pile housing 12 is free to expand and contract without affecting the position of the screw 33 relative to the carbon pile 6 as it is mounted independent of the housing 12 upon the post 26. in other words, the carbon pile is supported between the carbon buttons 9 and 10 independently of the housing 12.

Referring now to Figure 2, wherein like parts have been given the same reference numerals as in Figure l, and a detailed description of such parts will be omitted for simplicity.

A regulator indicated generally by the numeral 40 has a carbon pile 6 composed of stacks of carbon discs 7 disposed between a relatively fixed carbon button 9 and a movable carbon button ill. The stack is surrounded by a ceramic tube or sleeve 11. The sleeve 11 is secured in housing 12 by conventional means. The housing 12 is provided with cooling fins 13 for dissipating heat from the stack 6 and is usually made of metal having good heat conducting qualities.

The pressure applied to the stack 6 is controlled by the operation of the electromagnet 3 in opposition to a spring member 41. The spring member 4-1 is preferably of a diaphragm type and is adapted to seat in a counterbore portion 42 of electromagnet housing 43. The spring member 41 carries an armature member 44 spaced in operative relationship with the core 16. In addition, the armature member 44 supports the carbon disc 10.

Posts 45, formed of a material having a very low temperature coefiicient of expansion, for example, nickel alloy sold under the trade name of lnvar are riveted to a metal plate 46. The posts 45 extend upward through openings 30 in the housing 12 and the plate 46 is secured to the housing 12 in the counterbore portion 23 by screws 47.

A plate 25 of suitable insulating material is mounted on the other end of the posts 45'by screws 27. A cap 31 is secured to the plate 25 by screws 32. The cap 31 screw threadedly engages a screw 33 which may be locked in position by a suitable flat spring lock indicated by the numeral 34. The screw 33 is adapted for operatively engaging the carbon button 9 and has a cleft portion 35 to facilitate adjustments. A cover 37 may be provided for the cap and screw assembly.

The operation is similar to that illustrated in Figure l. The housing 12 is free to contract and expand with change in temperature without havingany appreciable effect upon the carbon pile 6. Y

Although only two embodiments of the'invention have been illustrated and described, various changes in the form and relative arrangement of the parts, which will now appear to those skilled in the art, may be made without departing from the scope of the invention.

What is claimed is:

1. An electrical regulator, comprising in combination, a stack of discs of resistance material disposed between a fixed pressure plate and a movable pressure plate, an electromagnet disposed for operation to control force applied to the movable pressure plate and thereby control the pressure applied to the stack, a housing including a fin-like section for said stack of material having good heat conductivity, means including posts of material having a relatively low temperature coeflicient of expansion and a base plate for mounting said fixed pressure plate independent of said fin-like section relative to said movable pressure plate whereby said fixed pressure plate is not afiected by contraction and expansion of said fin-like section.

2. In an electrical regulator having a stack of discs of resistance material disposed between a fixed pressure plate s and a movable pressure plate and an electromagnet disposed for operation to control force applied to the movable pressure plate and thereby control the pressure applied to the stack, the combination comprising a housing having a section surrounding said stack and having cooling fins extending outwardly therefrom, a base plate integral with said housing adjacent said movable pressure plate, a plurality of posts having a very low temperature coefiicient of expansion mounted on said base plate and extending through said cooling fin section and means for mounting said fixed pressure plate on said posts whereby said fixed pressure plate is not affected by temperature changes in said cooling fin section of said housing.

3. In an electrical regulator having a stack of discs of resistance material disposed between a fixed pressure plate and a movable pressure plate and an electromagnet disposed for operation to control force applied to the movable pressure plate and thereby control the pressure applied to the stack, the combination comprising a metallic housing surrounding said pile including a section having a plurality of cooling'fins extending radially thereof, said cooling fin section having a relatively high temperature coefiicient of expansion, a base plate secured to said housing adiacent to said movable pressure plate, and a plurality of posts having a relatively low temperature coefficient of expansion mounted on said base plate and extending through openings in said cooling fins for mounting said fixed pressure plate in a fixed position relative to said base plate independent of said cooling fin section.

4. in an electrical regulator having a stack of discs of resistance material disposed between a fixed pressure plate and a. movable pressure plate and an electromagnet disposed for operation to control force applied to the movable pressure plate and thereby control the pressure ap plied to the stack, the combination comprising a housing including a base section and a fin-lilre section, a plurality of posts having a low temperature coefiicient of expansion and having one end thereof secured to said base section and extending through openings in said tin-like section, a cap member secured to said other ends of said posts, a screw member screw threadedly engaging said cap member and adapted to engage said fixed pressure plate.

References Cited in the file of this patent UNITED STATES PATENTS 2,427,805 Neild Sept. 23, 1947 

